标题： 基于纸张的比色传感器，用于使用环氧树脂-银纳米复合材料检测水中的氯离子 显示英文标题

标题： Paper-based colorimetric sensor for detection of chloride anions in water using an epoxy-silver nanocomposite

摘要： 一种印刷在纸上的环氧树脂-银纳米复合材料用于水溶液中氯离子（Cl$^-$）的比色检测。 这种基于纸张的传感器提供了一个有前景的平台，具有简单的制备、鲜明的颜色、快速的肉眼响应和对Cl$^-$检测的高特异性等吸引人的优势。 在有水存在时，该传感器会从橙黄色变为栗褐色，并在有Cl$^-$存在时变为绿褐色。 在20-400 mM浓度范围内观察到对数Cl$^-$浓度与515 nm处消光强度差之间良好的线性关系（$R^2$=0.9754），检测限（LOD）为14 mM，远高于大多数Cl$^-$比色传感器通常限制的浓度。 还提出了一种基于Cl$^-$氧化蚀刻各向异性银纳米颗粒（20至250 nm）并随后形成链状聚集体的传感机制，从而导致强烈的粒子间等离子体耦合。 这种基于纸张的传感器可以区分 Cl$^-$与其他离子，如 F$^{-}$， OH$^{-}$， NO$_{3}^{-}$， SO$_{4}^{2-}$， HPO$_{4}^{2-}$， H$_{2}$PO$_{4}^{-}$， H$^{+}$， K$^{+}$， Na$^{+}$， NH$_{4}^{+}$， Zn$^{2+}$和 Co$^{2+}$，以及这些离子的混合物。 纳米传感器还被测试用于识别海水和商业电解质溶液中的 Cl$^{-}$，甚至使用小至 4 $\mu$L 的体积，表明其易于包含在便携式设备中。 这种新颖的比色平台无疑对识别环境和生理系统中的 Cl$^-$具有用途。 显示英文摘要

摘要： An epoxy-silver nanocomposite printed on paper was prepared for colorimetric detection of chloride anions (Cl$^-$) in aqueous solution. This paper-based sensor provides a promising platform with attractive advantages such as simple fabrication, intense colors, fast naked-eye response, and high specificity toward Cl$^-$ detection. The sensor undergoes a color change from yellow-orange to chestnut-brown in the presence of water and turns to green-brown in the presence of Cl$^-$. A good linear relationship ($R^2$=0.9754) between logarithmic Cl$^-$ concentration and the extinction intensity difference at 515 nm was observed at concentrations in the 20-400 mM range with a limit of detection (LOD) of 14 mM, far beyond the usual concentrations at which most of the Cl$^-$ colorimetric sensors are limited. It was also proposed a sensing mechanism based on the oxidative etching of anisotropic silver nanoparticles (from 20 to 250 nm) by Cl$^-$ and subsequent formation of chain-like aggregates, resulting in strong interparticle plasmonic coupling. This paper-based sensor can distinguish Cl$^-$ from other ions such as F$^{-}$, OH$^{-}$, NO$_{3}^{-}$, SO$_{4}^{2-}$, HPO$_{4}^{2-}$, H$_{2}$PO$_{4}^{-}$, H$^{+}$, K$^{+}$, Na$^{+}$, NH$_{4}^{+}$, Zn$^{2+}$, and Co$^{2+}$ and from mixtures of these ions. The nanosensor was also tested to recognize Cl$^{-}$ in seawater and a commercial electrolyte solution, even using volumes as small as 4 $\mu$L, suggesting its easy inclusion in portable devices. This novel colorimetric platform is undoubtedly useful for recognizing Cl$^-$ in environmental and physiological systems.